linux-kernel - Re: [PATCH 3/3] floppy: suppress UBSAN warning in setup_rw

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <b1bae333-fe86-2c48-b872-fb72ebe2d53e@linux.com>
Date:   Wed, 22 Apr 2020 11:32:40 +0300
From:   Denis Efremov <efremov@...ux.com>
To:     Christoph Hellwig <hch@...radead.org>
Cc:     Willy Tarreau <w@....eu>, linux-block@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] floppy: suppress UBSAN warning in setup_rw_floppy()



On 4/22/20 11:24 AM, Christoph Hellwig wrote:
> 
> I don't think we can just change FD_RAW_CMD_SIZE or cmd as that could
> break userspace.

The second patch adds these defines FD_RAW_CMD_SIZE, FD_RAW_REPLY_SIZE.
Currently they are not in the uapi. Ok, I will send v2.

But otherwise, yes something very much like that:
> 
>>  #define FD_RAW_CMD_SIZE 16
>>  #define FD_RAW_REPLY_SIZE 16
>> +#define FD_RAW_FULL_CMD_SIZE (FD_RAW_CMD_SIZE + 1 + FD_RAW_CMD_SIZE)
>>  
>>         unsigned char cmd_count;
>> -       unsigned char cmd[FD_RAW_CMD_SIZE];
>> -       unsigned char reply_count;
>> -       unsigned char reply[FD_RAW_REPLY_SIZE];
>> +       union {
>> +               struct {
>> +                       unsigned char cmd[FD_RAW_CMD_SIZE];
>> +                       unsigned char reply_count;
>> +                       unsigned char reply[FD_RAW_REPLY_SIZE];
>> +               };
>> +               unsigned char full_cmd[FD_RAW_FULL_CMD_SIZE];
>> +       };
> 
>>         int track;
>>
>> Denis
> ---end quoted text---
>